Reusable auto injectors which can be loaded with a container subassembly, such as a syringe, are known in the prior art. U.S. Pat. No. 5,599,309 discloses an auto injector for use with proprietary syringes. That prior art discloses a device comprising a drive member that receives the rear end of a plunger of a syringe and a trigger for releasing the drive member such that a medicament can be injected. Drawbacks with that prior art are that needle is outside the device and visible to the user after the device has been removed from the injection site and that the re-loading is complicated and time consuming.